Anyone knows if there is some kind of accessories I can buy not to have to keep my finger on the button for 2 minutes when I use the B Exposure option?
I'm guessing that a cable release adaptor might do the job - you'd still have to push/squeeze the release for 2 mins but it would likely be more comfortable.
You can buy them, or make your own as demonstrated by Owen in this thread.
I was also going to recommend a cable release, however, I'm still unclear as to what the B Exposure option is and am also curious to know if your camera is capable of a 2min expsoure. That's pretty impressive for a prosumer camera.
B exposure I would assume is bulb exposure, which allows you to take a longer exposure than the minimum exposure by holding down the shutter for as long as you would like the exposure to go. I can do the same thing on my coolpix 995 I just upgraded to a few weeks ago.